21121212202101 has 24 divisors (see below), whose sum is σ = 35033589620640. Its totient is φ = 12127011789600.

The previous prime is 21121212202007. The next prime is 21121212202121. The reversal of 21121212202101 is 10120221212112.

21121212202101 is a `hidden beast` number, since 2 + 112 + 121 + 220 + 210 + 1 = 666.

It is not a de Polignac number, because 21121212202101 - 2¹⁵ = 21121212169333 is a prime.

It is a super-2 number, since 2×21121212202101² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121212202121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5614355430 + ... + 5614359191.

It is an arithmetic number, because the mean of its divisors is an integer number (1459732900860).

Almost surely, 2^{21121212202101} is an apocalyptic number.

It is an amenable number.

21121212202101 is a deficient number, since it is larger than the sum of its proper divisors (13912377418539).

21121212202101 is a wasteful number, since it uses less digits than its factorization.

21121212202101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11228714657 (or 11228714654 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21121212202101 its reverse (10120221212112), we get a palindrome (31241433414213).

The spelling of 21121212202101 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twelve million, two hundred two thousand, one hundred one".